Exchange anisotropy in amorphous Gd-Co films

Journal Article · Tue Nov 15 04:00:00 EST 1988 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.342337· OSTI ID:6749816

Toxen, A M; Geballe, T H; White, R M

It was previously reported that multilayer samples of Co/GdCo/sub 2/ annealed at 500 /sup 0/C exhibited exchange anisotropy. One observes a B-H hysteresis loop centered at a finite field, the ''exchange'' field. To identify the ''hard'' magnetic phase(s) responsible for the shifted loops we have studied thin films of GdCo/sub x/ as well as multilayers of Co/GdCo/sub x/, where x varies from 2 to 8.5. We saw shifted loops in two distinct groups of samples, neither of which is multilayered. The first group was GdCo/sub x/ in the composition range between GdCo/sub 3/ and GdCo/sub 5/. The loop displacement at room temperature is about 5 Oe. The coercivities of these samples are about 10 Oe. The second group of samples had a composition close to GdCo/sub 2/. For these samples most of the B-H loop is centered at zero field with a coercivity of 1--2 Oe. However, at +- 80 Oe there are small loops which account for about 20% of the total magnetization. X-ray measurements indicate that both groups of samples are microcrystalline or amorphous. The second set of samples discussed above exhibit a maximum in diffracted intensity at 2theta = 36/sup 0/, where GdCo/sub 2/ has a strong (220) peak. The first group of samples have a broad maximum at 38/sup 0/, where neither GdCo/sub 3/ nor GdCo/sub 5/ has peaks. Gd/sub 2/Co/sub 7/ has a very weak peak at this angle and Gd/sub 2/Co/sub 17/ has strong peaks but would have to be metastable.

• Research Organization: Stanford University, Stanford, California 94305-4045
• OSTI ID: 6749816
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 64:10; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ALLOYS
AMORPHOUS STATE
ANISOTROPY
COBALT ALLOYS
COBALT BASE ALLOYS
COHERENT SCATTERING
DIFFRACTION
GADOLINIUM ALLOYS
HYSTERESIS
LAYERS
MAGNETIC PROPERTIES
MAGNETIZATION
PHYSICAL PROPERTIES
RARE EARTH ALLOYS
SCATTERING
X-RAY DIFFRACTION